:root {
  --canvas: #f4f1eb;
  --paper: #fbfaf7;
  --ink: #191817;
  --soft: #4f4b45;
  --muted: #80786d;
  --line: rgba(25, 24, 23, .14);
  --line-strong: rgba(25, 24, 23, .24);
  --charcoal: #22211e;
  --bronze: #a5774c;
  --ivory: #fffefa;
  --radius: 8px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at 8% 0%, rgba(165, 119, 76, .12), transparent 28%),
    linear-gradient(90deg, rgba(25, 24, 23, .035) 1px, transparent 1px) 0 0 / 72px 72px,
    linear-gradient(rgba(25, 24, 23, .026) 1px, transparent 1px) 0 0 / 72px 72px,
    var(--canvas);
  background-attachment: fixed, fixed, fixed;
  font-family: "Aptos", "Segoe UI", "Microsoft YaHei", "PingFang SC", sans-serif;
  font-size: 14px;
  line-height: 1.55;
}

a {
  color: inherit;
  text-decoration: none;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  min-height: 52px;
  padding: 8px clamp(20px, 4vw, 56px);
  border-bottom: 1px solid var(--line);
  background: rgba(244, 241, 235, .9);
  backdrop-filter: blur(18px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 16px;
  font-weight: 760;
}

.mark {
  display: grid;
  width: 26px;
  height: 26px;
  place-items: center;
  color: var(--ivory);
  border-radius: 50%;
  background: var(--charcoal);
  font-size: 13px;
  font-weight: 800;
}

.nav {
  display: inline-flex;
  gap: 2px;
  color: var(--muted);
  font-size: 13px;
  white-space: nowrap;
}

.nav a {
  padding: 7px 10px;
  border-radius: 999px;
}

.nav a:hover,
.nav a.active {
  color: var(--ink);
  background: rgba(255, 255, 255, .58);
}

.top-action {
  justify-self: end;
  min-height: 32px;
  padding: 6px 13px;
  border: 1px solid var(--charcoal);
  border-radius: 999px;
  color: var(--ivory);
  background: var(--charcoal);
  font-size: 13px;
  font-weight: 760;
}

main {
  max-width: 1120px;
  margin: 0 auto;
  padding: clamp(34px, 5vw, 72px) clamp(20px, 4vw, 56px) 72px;
}

.docs-main {
  max-width: 1280px;
}

.hero {
  display: grid;
  gap: 22px;
  padding-bottom: 34px;
  border-bottom: 1px solid var(--line);
}

.kicker {
  color: var(--soft);
  font-family: Georgia, "Times New Roman", "Microsoft YaHei", serif;
  font-style: italic;
  font-size: 13px;
}

h1 {
  max-width: 900px;
  margin: 0;
  font-family: Georgia, "Times New Roman", "Microsoft YaHei", serif;
  font-size: clamp(34px, 5vw, 58px);
  line-height: 1;
  font-weight: 500;
}

.lead {
  max-width: 780px;
  margin: 0;
  color: var(--soft);
  font-size: clamp(15px, 1.5vw, 18px);
  line-height: 1.78;
  letter-spacing: .035em;
}

.section {
  padding: 34px 0;
  border-bottom: 1px solid var(--line);
}

.docs-hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 340px;
  gap: clamp(28px, 5vw, 68px);
  align-items: end;
  padding: clamp(48px, 8vw, 98px) 0 42px;
  border-bottom: 1px solid var(--line);
}

.docs-hero h1 {
  max-width: 720px;
  font-size: clamp(52px, 7vw, 92px);
  letter-spacing: 0;
}

.docs-hero .lead {
  max-width: 760px;
}

.docs-brief {
  display: grid;
  gap: 10px;
  align-self: stretch;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(251, 250, 247, .72);
  box-shadow: 0 18px 48px rgba(39, 34, 28, .08);
}

.docs-brief span,
.doc-label,
.doc-row > span {
  color: var(--bronze);
  font-family: Georgia, "Times New Roman", "Microsoft YaHei", serif;
  font-size: 12px;
  font-style: italic;
}

.docs-brief strong {
  display: block;
  font-size: 18px;
  line-height: 1.35;
}

.docs-brief p {
  color: var(--soft);
  font-size: 14px;
}

.docs-layout {
  display: grid;
  grid-template-columns: 180px minmax(0, 1fr);
  gap: clamp(28px, 4vw, 56px);
  align-items: start;
}

.docs-rail {
  position: sticky;
  top: 78px;
  display: grid;
  gap: 4px;
  padding-top: 34px;
  color: var(--muted);
  font-size: 13px;
}

.docs-rail a {
  padding: 8px 0;
  border-bottom: 1px solid rgba(25, 24, 23, .08);
}

.docs-rail a:hover {
  color: var(--ink);
}

.docs-content {
  min-width: 0;
}

.section-head {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(220px, 340px);
  gap: 24px;
  align-items: end;
  margin-bottom: 18px;
}

.section-head p {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.65;
}

.doc-list {
  display: grid;
  border-top: 1px solid var(--line);
}

.doc-row {
  display: grid;
  grid-template-columns: 58px minmax(0, 1fr) auto;
  gap: 18px;
  align-items: center;
  padding: 18px 0;
  border-bottom: 1px solid var(--line);
}

.doc-row h3 {
  margin: 0 0 5px;
}

.doc-row p {
  margin: 0;
  color: var(--soft);
  font-size: 14px;
  line-height: 1.65;
}

.doc-list.compact .doc-row {
  grid-template-columns: 88px minmax(0, 1fr);
}

.doc-card {
  display: flex;
  flex-direction: column;
  min-height: 100%;
}

.doc-card .button {
  align-self: flex-start;
  margin-top: auto;
}

.doc-label {
  display: inline-block;
  margin-top: 14px;
}

h2 {
  margin: 0 0 14px;
  font-size: clamp(24px, 2.6vw, 34px);
  line-height: 1.12;
  font-weight: 760;
}

h3 {
  margin: 20px 0 8px;
  font-size: 18px;
  font-weight: 760;
}

p {
  margin: 0 0 14px;
}

ul,
ol {
  margin: 0 0 16px;
  padding-left: 22px;
}

.grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}

.tile,
.faq details,
.fact-table {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(251, 250, 247, .78);
}

.tile {
  padding: 16px;
  box-shadow: 0 10px 28px rgba(39, 34, 28, .05);
}

.tile strong {
  display: block;
  margin-bottom: 7px;
}

.case-image {
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(255, 254, 250, .6);
}

.case-image img {
  display: block;
  width: 100%;
  height: auto;
  filter: saturate(.88);
}

.fact-table {
  width: 100%;
  border-collapse: collapse;
  overflow: hidden;
}

.fact-table th,
.fact-table td {
  padding: 12px;
  border-bottom: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
}

.fact-table tr:last-child th,
.fact-table tr:last-child td {
  border-bottom: 0;
}

.faq {
  display: grid;
  gap: 10px;
}

.faq details {
  padding: 12px 14px;
}

.faq summary {
  cursor: pointer;
  font-weight: 760;
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 18px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 38px;
  padding: 8px 14px;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  background: rgba(255, 255, 255, .58);
  font-size: 13px;
  font-weight: 760;
  transition: transform .18s cubic-bezier(.22, .72, .2, 1), border-color .18s ease, background .18s ease;
}

.button:hover {
  transform: translateY(-1px);
  border-color: var(--line-strong);
  background: rgba(255, 255, 255, .86);
}

.button.primary {
  color: var(--ivory);
  border-color: var(--charcoal);
  background: var(--charcoal);
}

@media (max-width: 780px) {
  .topbar {
    grid-template-columns: 1fr;
    gap: 8px;
  }

  .nav,
  .top-action {
    justify-self: start;
    overflow-x: auto;
    width: 100%;
  }

  .grid {
    grid-template-columns: 1fr;
  }

  .docs-hero,
  .docs-layout,
  .section-head,
  .doc-row,
  .doc-list.compact .doc-row {
    grid-template-columns: 1fr;
  }

  .docs-hero {
    padding-top: 34px;
  }

  .docs-hero h1 {
    font-size: clamp(42px, 14vw, 58px);
  }

  .docs-brief {
    align-self: auto;
  }

  .docs-rail {
    position: static;
    grid-auto-flow: column;
    grid-auto-columns: max-content;
    overflow-x: auto;
    padding: 14px 0 0;
  }

  .doc-row {
    gap: 8px;
    align-items: start;
  }

  .doc-row .button {
    width: 100%;
  }
}